Vl-anooraph co



J. H. PEARSON.

RECIPROCATING LENS SURFACING APPARATUS.'

APPLICATION HLED FEB- 28.191].

Patented Sept. 30, 1919.

2 SHEETSSHEET 1.

INVENTOR Jo/z/i ffin/ y Pearsor;

1 v ATTORNEYS J. H. PEARSON. RECIPROCATING LENS SURFACING APPARATUS.

APPLICATION FILED FEB. 28. I911.

1,3 1 7,45 3 Patented Sept. 30, 1919.

2 SHEH S-SHEET 2.

N V E N TOR Job/7 fihrre/ Pea/507 ,4 TTORIVF Y3 THE COLUMIIA Y'LANOORAFII' cm, WASHINGTON, I) c.

UNITED STATES PATENT OFFICE.

JOHN HARVEY PEARSON, OF INDIANAPOLIS, INDIANA, ASSIGNOR 'IO ONEPIECE BIFOCAL LENS COMPANY, OF INDIANAPOLIS, INDIANA, A CORPORATION.

RECIPROGATING LENS-SURFAGING- APPARATUS,

Specification of Letters Patent.

Patented Sept. 30, 1919.

Application filed February 28, 1917. Serial No. 151,601.

Surfacing Apparatus; and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, in which like numerals refer to like parts.

The object of this invention is to improve the construction and operation of apparatus for grinding and polishing lenses of the character of that shown in Letters Patent to Charles Conner, No. 1,162,039, patented November 30, 1915. The particular purpose for which such machines have been heretofore used has been to polish bifocal lenses.

As shown in said previous patent, the pin for holding the polishing button or element is stationary in operation, after it has been adjusted and set in the right angle or position. The purpose of this invention is to enable the polishing button or element to be oscillated automatically transversely of the blank or lens being treated.

v The object and effect of this transverse oscillatory movement of the polishing element is to polish and treat the lens or blank more effectively. For instance, often the first or preliminary polishing element with which the ground blank is treated, leaves the center of the inner and the minor or reading surface rough, incomplete or elevated, because such polishing element operates around such point of the lens as a center. Afterward the lens blank is operated on by the polishing apparatus herein shown and the polishing element for the inner, minor or reading surface travels or oscillates laterally as they are doing the polishing operation so as to smooth, complete and polish said central portion of such inner, minor or reading surface. 7

To understand this, it must be borne in mind that in making such bifocal lenses, the blank is ground and polished with the central circular, minor or reading surface surrounded by an outer annular, major or distance surface, and afterward the blank is centrally split to make two lenses. However, instead of a single piece of glass, ground and polished as explained and afterward split in two for two lenses, a plurality of pieces of glass may be secured on the lens holder, one for each lens, and be ground and polished, the same as a single piece of glass.

This invention is of particular value, however, in making those types of bifocal lenses having a relatively large minor or reading surface. That may be in small sized lenses having a large reading surface, say 3 1 mm. in size, and also the jumbo or relatively large bifocal lenses which likewise'have said large minor or reading surface. In these two types of lens blanks, the minor or reading surface extends beyond the center of the blank as it is ground and polished, and it is desirable that said central roughness, projection or elevation be polished away in order to make said minor or reading surface of the bifocal lens smooth, complete and perfect.

The chief feature of the apparatus whereby this object is accomplished consists in a double pivoted means for carrying the pin which holds the polishing element, whereby it may be moved laterally as well as vertically, and also in associating therewith a cam or other means for causing the lateral oscillatory movement of the pin or means for holding the polishing element.

The full nature of the invention will be understood from the accompanying drawings and the following description and claims.

In the drawings, Figure l is a side elevation of the machine showing means for carrying the pin which holds the polishing element in substantially a vertical position. Fig. 2 is a plan view of the machine shown in Fig. 1, excepting that the upper part of the pin and the weight thereon are cut away. Fig. 3 is a section on the line 33 of Fig. 2, with parts broken away. Fig. 4 is a section through the polishing element and the lens holder and a lens, showing the polishing button in one position by full lines and in an-' other'position by dotted lines. Fig. 5 is a section on the line'5-5 of Fig. 1. Fig. 6 is a front elevation of a part of the machine showing a modified form with the pin mounted in angular position and for holding and operating a. large button or element for polishing the outer annular long-distance surface of the lens. Fig. 7 is a figure similar'to that of Fig. 6, showing, however, the pin carrying a polishing button or element for treating the central, minor or reading surface of the lens.

In the drawings there is shown herein a base plate '10 with a vertical shaft bearing 11 for a shaft 12, shown by dotted lines in Fig. 1 and by full lines in Fig. 2. On this shaft there is a pulley 13 driven by a belt 14 from some suitable source of power. It is immaterial how this part ofthe mechanism is constructed.

On the-shaft-12 there isa sprocket wheel 112, over which a sprocket chain 15 operates and transmits power to a sprocket wheel 116, on an arbor 16 that carries the lens holder 17 on which the lens blank 18 is mounted.

On the table 10 there are .two bearing posts 20 and21 which carry adjustable center pins 22 for mounting a substantially triangular frame 23 which extends forwardly from said bearing to a point near the lens holder and so that the latter end of said frame may be lifted up or let down, sub-- .stantially the same as the corresponding portion of said previous patent to Charles W. Conner. The front free end of said frame has a straight radially and vertically exextends loosely through a brass bushing or sleeve 28 which is rigidly secured and clamped in a clamping head29. This clamping head extends' vertically and is mounted by a screw 30 in ahead 31 whereby the clamping head 29 and the pin 26 may be adjusted from the truly vertical position, as shown in Fig. 1, to the angular position shown inFigs. 5 and 6. The pin 26 has secured upon its upper end the usual weighting apparatus 32.

The head 31 is secured to the forward up-turned end 33 of abar 34, which has a vertical rear end, as seen in Fig. 3, that is mounted-on a lower bearing pin 35 and adjustable upper bearing pin 36. The bearing pin 35 is mounted in the wide portion of the triangular frame 23 and the upper adjusting pin 36 is secured in an arm 37 extending from said frame-23.- Tlns enables the head 29 carryingthe pin 26 for holding the polishing element 27 to have lateral move- 1 ment.

,6and 7. Said-cam'is held against the surface 25 by a spring 45, one end of which is secured to the bar 24 and the other to a bracket 46 on the frame 23. Such movement of the frame 34 and cam 40 by said spring is limited by .an adjusting screw 47 mounted in a bracket 48 on the frame 23. The cam 40 is turned by a pulley 50 secured on a sleeve 51 which is secured to said cam. The pulley is driven by a belt 52 running from a pulley 53 on a shaft 54 in bearings 55 in a bracket 56 mounted upon the base plate 10. The shaft' 54 has a gear 57 on its lower end which is driven by a gear 58 on the upper end of the shaft 12.

In operation the lens holder is positively rotated by the chain 15. The polishing button or element 27 rests upon the lens blank and is held there by the pin 26 and the weight thereon and the pin is held in a truly vertical or angular position by the clamping head29 and means by which it is carried. The polishing element 27 is given lateral oscillatory movement by the cam 40 as it is turned by the belt 52 and pulley 50 and it bears against the surface 25 of the frame 23 and is held against said surface by the spring 45. The transverse movement of the polishing element 27 is limited by the size and arrangement of the cam 40 and also by the adjusting stop 47.

The machine, as a lens polisher in the manufacture of bifocal lenses, is adapted to polish either the outer annular distance surface or the inner minor or reading surface of the lens blank. The polishing element 27 shown in Figs. 1 and 5, is for polishing the outer or distance surface and has an annular polishing rib on the underside thereof. as shown in Fig. 6, having a diameter which enables the rib to span at all times the innerreading surface without engaging it. As the machine operates, the lateral movement of the polishing tool moves it transversely from the position shown by full lines in Fig. 5, where it is at its right hand limit of movement and, therefore, the right hand edge of said rib near the right hand edge of the lens andthe left hand edge of said rib is at the left hand edge of the inner or reading sur face and on a dividing line between the two surfaces. Therefore, while said polishing element is polishing said'outer annular dis tance surface, it is traveling laterally to and fro across the lens for a distance equal in engagement with a rotating lens, as is done in the afore-mentioned Conner Patent No. 1,162,039.

Fig. 7 shows the same form as in Fig. '6, excepting the polishing element GA is differently formed, being a plain button which engages and polishes only the inner or read ing surface.

The invention claimed is:

1. A lens surfacing apparatus including a lens holder, a surfacing element for treating a lens on said holder, means for holding said surfacing element in engagement with the lens on said holder and which means is pivotally mounted so as to be reciprocable transversely of said lens holder, a fixed means and means carried by said surfacing clement holder and engaging said fixed means for causing and controlling the limits of such transverse movement.

2. Alens surfacing apparatus including a lens holder, means for holding a surfacing element in engagement with the lens on said holder, one of said members being mounted so as to be reciprocable transversely of the other member, a rotatable eccentric disk carried by said reciprocable member, and an adjustably fixed stop which the periphery of said eccentric disk engages, whereby the means for holding the surfacing element will be reciprocaited transversely of the lens holder.

3. Alens surfacing apparatus including a lens holder, means for holding a surfacing element in engagement with a lens on said holder and arranged to be reciprocable transversely of the lens holder, a rotatable eccentric loosely mounted on the means for holding the surfacing element, and an adjustable fixed stop which one side of said eccentric engages, whereby the means for holding the surfacing element will be reciprocated transversely of the lens holder.

i. A lens surfacing apparatus including a lens holder, a surfacing element,.means for holding said surfacing element in engagement with the lens on said holder and which means is pivotally mounted so as to be free to move toward and away from the lens holder and also transversely thereof, a fixed means and a rotatable eccentric mounted on the surfacing element holder.

and tangentially engaging said fixed means for causing and controlling the limits of such transverse movement.

5. A lens surfacing apparatus including a lens holder, a surfacing element in engagement with the lens on the holder and which is mounted so it can be moved transversely of the lens holder, an eccentric loosely mounted on said pin, means for rotating the eccentric, and fixed means against which said eccentric at one side bears during its operation and whereby the pin is given transverse movement.

6. A lens surfacing apparatus including a lens holder, a surfacing element, a pin for holding said surfacing element, a frame in which the pin is mounted and which is pivr otally mounted so that the pin will be capable of movement transversely of the lens holder, and means carried by the pin for causing such transverse movement.

7. A lens surfacing apparatus including a lens holder, a lens surfacing element, a pin for holding said surfacing element, a frame in which said pin is mounted and which frame is pivoted so that it will be free to swing transversely of the lens holder, yielding means tending to move said frame in one direction, means for limiting such movement, and means for moving the frame in the opposite direction, whereby the surfacing element will be caused to move within limits transversely of the lens holder.

8. A lens surfacing apparatus including a lens holder, a lens surfacing element, a pin for holding said surfacing element, a frame in which said pin is mounted and which frame is pivoted so that it will be free to swing transversely of the lens holder, an eccentric mounted on said pin, a fixed surface which said eccentric engages, whereby it will move the pin transversely of the lens holder, means for rotating said eccentric, yielding means tending to move said frame so that the eccentric will engage said fixed surface, and an adjustable stop for limiting such movement of said frame.

9. A lens surfacing apparatus including a lens holder, a lens surfacing element, a pin for holding said surfacing element, a frame in which said pin is mounted and which frame is pivoted so that it will be free to swing transversely of the lens holder, an eccentric mounted on said pin, means for rotating said eccentric, a frame pivoted so as to be vertically oscillatory and project ing beside said eccentric and upon which frame said pin carrying frame is pivoted, a spring carried by said second frame tending to move the eccentric on said pin carrying frame toward said second frame, and a screw stop on said second frame in position to limit the movement of the pin carrying frame.

In witness whereof, I have hereunto affixed my signature.

JOHN HARVEY PEARSON.

Copies of this patent may be obtained for five dents each, by addressing the Commissioner of Patents, Washington, D. G. 

